this seems possible. while Japan is a very densely populated country with a good amount of development money on their hands, this is very well times. this is a very sustainable project for a country like Japan and will reserve natural areas for nature. also, depending on it's design, it CAN be designed to resist earthquakes. by 2045, im sure they will have much better engineering technology to make something like this on water. but with a 29 year completion date, the design and renders and definitely the height are guaranteed to change.

the Jeddah Kingdom tower was not long ago a proposal by the name of "mile tower".

a building like this doesn't have to be funded and inhabited by only Japanese people, but most definitely people and corporations from around the world who want to promote sustainability and have a fat wallet would also promote this and buy into it.

According to article it is supposed to be somekind of whole futuristic neigbourhood just in the middle of Tokyo Bay. Mile High Tower would be just part of whole project.

Quote:

The proposal includes coastal defense infrastructure that acts as a buffer, as well as island housing clusters that can accommodate half a million people seeking to leave high-risk coastal areas and reduce commute times. Hexagonal water-filled rings would allow sharing of resources such as freshwater reservoirs, public beach harbors and urban farming plots, while faceted breakwater bars and additional operable floodgates would provide additional defense. The scheme would serve as a transit hub, with tunnels, regional lines and even a new Hyperloop transport system liked that proposed by Elon Musk...

...The primary station would service the Sky Mile Tower, a high-density residential structure reaching over 1,600 meters in height. This megatall building, conceived as a set of three interconnected structures, would feature multi-level sky lobbies, shared public spaces, shopping areas, restaurants, hotels, libraries, gyms and clinics. Its stepped and tapered form, with various openings that allow the wind to pass through, ensure the structure’s sound aerodynamic performance.

It is said that towers are the best place to be in when a mega earthquake hits Tokyo. Simply because they got way more protective devices then all the lowrise buildings. Therefor proposing such towers as safe environments to live and work in is that crazy.

And building above water could also be better then all the large scale residential developments that are now being built on reclaimed land along Tokyo Bay. These areas in Tokyo, which are on the current sea level, only behind small levees, have seen a large number of residential towers going up over the last 20 years and more are in the works. New homes have been created for much more people in those areas then the projected 55.000 inhabitants of this proposed vision. These low areas, without serious protection against flooding are much more vulnerable for a rising sea level then this vision on poles way above the future sea level.

But just be clear, it's still just a vision by an American architecture firm and an American engineering firm. There are for now no solid plans to turn this into an actual project. It doesn't have any financial or governmental backing, it's idea by an architect, nothing more, nothing less.

This is much more a silly art project than anything else - what's with all the hexagons and fragments of hexagons? It looks like something from an early GITS: Stand Alone Complex storyboard...

As for 'building on water' - sure, why not? Been done a million times already. And probably not much more expensive, if at all, than the real estate values around Tokyo Bay anyway. I'd also imagine that it's naturally more resistant to tsunamis than land on the coast...